Good plasmons in a bad metal

• 成果类型: Article
• 署名作者: Ruta, Francesco L.; Shao, Yinming; Acharya, Swagata; Mu, Anqi; Jo, Na Hyun; Ryu, Sae Hee; Balatsky, Daria; Su, Yifan; Pashov, Dimitar; Kim, Brian S. Y.; Katsnelson, Mikhail I.; Analytis, James G.; Rotenberg, Eli; Millis, Andrew J.; van Schilfgaarde, Mark; Basov, D. N.
• 署名单位: Columbia University; Columbia University; United States Department of Energy (DOE); National Renewable Energy Laboratory - USA; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; University of Michigan System; University of Michigan; University of California System; University of California Berkeley; University of California System; University of California Berkeley; University of London; King's College London; Columbia University; Radboud University Nijmegen; Simons Foundation; Flatiron Institute; University of Colorado System; University of Colorado Boulder; University of Arizona
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12177
• DOI: 10.1126/science.adr5926
• 发表日期: 2025-02-14
• 页码: 786-791
• 关键词: polaritons; transport

摘要

Correlated metals may exhibit unusually high resistivity that increases linearly in temperature, breaking through the Mott-Ioffe-Regel bound, above which coherent quasiparticles are destroyed. The fate of collective charge excitations, or plasmons, in these systems is a subject of debate. Several studies have suggested that plasmons are overdamped, whereas other studies have detected propagating plasmons. In this work, we present direct nano-optical images of low-loss hyperbolic plasmon polaritons (HPPs) in the correlated van der Waals metal MoOCl2. HPPs are plasmon-photon modes that waveguide through extremely anisotropic media and are remarkably long-lived in MoOCl2. Photoemission data presented here reveal a highly anisotropic Fermi surface, reconstructed and made partly incoherent, likely through electronic interactions as explained by many-body theory. HPPs remain long-lived despite this, revealing previously unseen imprints of many-body effects on plasmonic collective modes.